Over 92 percent of dwellings have at least one smoke alarm, making them the most recognizable fire safety feature in residences. Unfortunately, they are the most under-regarded safety feature. About one third of them no longer work because people forget to test them, replace dead batteries or replace old smoke alarms. For details on smoke alarm problems, selection, maintenance and replacement, see Smoke Detectors.
In new homes, smoke alarms should be powered by the home's electrical system and have backup batteries. They should also be interconnected so that if one unit detects smoke, all of the units will sound. New owners and tenants need to confirm this feature so they know what to expect if a fire occurs.
New dwellings should have the the following number of smoke alarms. First, there should be one alarm located outside each bedroom area, close enough to be heard through closed bedroom doors. There should also be one in each bedroom. In addition, there should be at least one on every level. Thus, a 3-bedroom home with a basement should have a minimum of five smoke alarms.
In homes where the bedrooms are not located together, additional smoke alarms will be needed outside the other bedrooms. It is advisable to have more than one on each level if there are several rooms. Remember, smoke alarms cannot work until the smoke reaches them, so every additional smoke alarms cuts the potential response time in a fire.
MAINTAINING SMOKE ALARMS
Keeping smoke alarms operating is easy. The big problem is dust that can accumulate inside the unit. Remember, air is flowing through them, and air carries dust particles. Once a year, hold a vacuum cleaner up against them to suck out any dust that may have accumulated inside the unit. If the units are battery operated, replace the batteries every year unless you have installed long-life batteries. And never install a 10-year battery in an older smoke alarm. It may leave you with an inoperable smoke alarm.
REPLACING SMOKE ALARMS
Like any appliance, smoke alarms wear out after time. Ten years is the recommended replacement time. After operating 24 hours a day for ten years, even well-maintained smoke alarms have a 30 percent chance that they will fail to operate in a fire.
CARBON MONOXIDE (CO) DETECTORS
Every home should have one or more CO alarms. This applies to homes with electric appliances as well if you have an attached garage, a fire place, or if you use portable kerosene heaters, etc. In the case of attached garages, the home may be under negative pressure from time to time (more air flowing out through vents than is coming in). When this is the case, air from the garage can be sucked into the home to make up the difference. When you start your car, just delaying for a few seconds before you pull out of the garage can leave enough CO in the garage to cause a problem.
CO alarms are necessary because there is no other way to detect its presence until it is too late. The gas has no odor, no color and no smell. Firefighters need special detection equipment to find the source. Back when CO alarms first hit the market, many fire departments were not trained or equipped to find CO. The firefighters would often respond to a CO alarm and tell the owner that there was no problem so it must be a faulty CO detector. After all, they couldn't see, taste or smell anything and everyone in the home appeared to be okay. They were wrong but did not know it because they did not have the equipment to find it.
The people appeared to be okay because the CO alarms are designed to sound before symptoms of CO poisoning appear. This was required so that people would have time to react while they were still clear-headed. Thankfully, most fire departments have now gotten the necessary training and equipment, and are less likely to miss the problem.
National standards recommend that a CO alarm be placed near the bedrooms close enough to hear it when the bedroom doors are closed. If the bedrooms are not together, additional CO alarms will be needed. In larger homes, just one CO alarm may not be close enough to other parts of the home to be heard. For example, if the CO alarm is upstairs and you have a family room on the lower level, you might need an additional unit to be close enough to hear it. If the room in in the basement, there will be two levels separating you from the CO alarm, so it is less likely that you will hear it. In this case, a CO alarm on each level is prudent.
You can buy battery-operated CO alarms or ones that need 110 volt power. Both types meet the same Underwriters laboratory requirements. In the past, the battery-operated units were more sensitive than the 110 volt type and some people preferred to be warned when even low levels of Co were present. The standards have changed, and CO alarms manufactured today only respond to higher levels of CO that are an imminent threat.
There is a new CO alarm on the market that goes into the furnace where the air is returned to be reheated. The logic of this device is that all of the air being circulated throughout the home will be recirculated through the furnace's cold-air return ducts, so one CO alarm in the duct will detect CO that is anywhere in the home. This logic holds as long as the furnace motor is running, so anyone installing this type of alarm needs to keep the motor running constantly, even in the months when the furnace is not being used. Another issue is the ability to hear the alarm. If you install one, make sure that it is loud enough to be heard in every room over the typical noise levels. It also needs to be loud enough to waken you when you are sleeping.